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Samsung SSD 840 PRO no longer being recognized by bios
http://forum.hddguru.com/viewtopic.php?f=10&t=40081		 Page 1 of 1
Author:  xga [ June 27th, 2020, 4:16 ]
Post subject:  Samsung SSD 840 PRO no longer being recognized by bios
Hi Guys,

Hope you can help me!

My main desktop PC has two Samsung SSD 840 PRO 256GB (MZ7PD256) running in RAID 0. Today I had a power failure whilst the computer was on and when the power was restored, the computer could no longer boot. Checking the BIOS, I noticed that only one of the 840 PRO's was being detected. I've removed the failed SSD from the computer and tested it with a USB to SATA adapter on another computer but it's still not being detected.

Apart from taking the SSD to a data recovery centre, do I have any other options I could try to get it working again. Is it possible that the firmware could have become corrupt and I could try flashing it similar to the technique in this post -https://forums.tomshardware.com/threads/samsung-850-pro-ssd-corrupted-firmware-fix-read-first.2193040/ ?

Thanks in advance for any assistance you can offer.

Cheers
Author:  DR-Kiev [ June 27th, 2020, 10:19 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
If you wanna try that method, save byte-to-byte image first from donor ssd, just in case.
Author:  xga [ June 27th, 2020, 22:14 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
DR-Kiev wrote:
If you wanna try that method, save byte-to-byte image first from donor ssd, just in case.


Thanks for your reply, DR-Kiev however, I wasn't able to get it to take the firmware when I hot swapped over to the faulty SSD.

Is there any easy way to determine if the SSD is powering on? I'm starting to think that some of the components might have been damaged either when the power went out or came back on. I assume that if I measure 5v around the controller IC then that's going to be the best way of telling?
Author:  fzabkar [ June 28th, 2020, 20:29 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
FWIW, the voltage test points for the 840 Evo are in @sourcerer's "Missing Manual":

http://www2.futureware.at/~philipp/ssd/TheMissingManual.pdf

If you need specific help with your Pro SSD, please provide detailed photos of both sides of the PCB.
Author:  xga [ July 1st, 2020, 12:53 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
fzabkar wrote:
FWIW, the voltage test points for the 840 Evo are in @sourcerer's "Missing Manual":

http://www2.futureware.at/~philipp/ssd/TheMissingManual.pdf

If you need specific help with your Pro SSD, please provide detailed photos of both sides of the PCB.


Thank you, fzabkar. I appreciate any advice you can suggest. Photos of both sides of the PCB are below.

Image

Image
Author:  fzabkar [ July 2nd, 2020, 0:57 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
The voltage test points are marked in the attachments.

Attachments:
regs2.jpg
regs2.jpg [ 132.62 KiB | Viewed 11156 times ]
regs1.jpg
regs1.jpg [ 106.43 KiB | Viewed 11156 times ]
Author:  outbreak198x [ March 24th, 2024, 15:22 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
Hello,

i have SM841 - same as 840pro - can't enter Safe Mode to read out with PC3000, and it stays BSY when entering normal Mode

so i measured the voltages named like in picture, and there are some with 0V - is it correct, or is there another pic where i can see what voltages there should be :D

V1 = 1,93
V2 = 0
V3 = 2,95
V4 = 1,84
V5 = 0
V6 = 1,16
V7 = 1,05
V8 = 0
Author:  fzabkar [ March 24th, 2024, 16:27 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
Check the 3 ENable pins of the RT9991.

https://www.richtek.com/assets/product_file/RT9991/DS9991-02.pdf

I don't have a datasheet for the LM10515SQ, so I don't know what is going on there.
Author:  outbreak198x [ March 24th, 2024, 16:36 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
EN1 0V
EN2+3 5V
Author:  fzabkar [ March 24th, 2024, 16:42 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
Either the V2 output is shorted to ground, or the RT9991 converter is faulty.

I would also test for shorts at V5 and V8.
Author:  outbreak198x [ March 24th, 2024, 16:55 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
hm - it looks like no shorts on all 3 0V voltges. always >30kOhm - so maybe it's really dead - ill check some things - maybe i'll find something out :) thx for now.
Author:  fzabkar [ March 24th, 2024, 17:06 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
I would replace RT9991. Perhaps V5 and V8 are asleep, and V2 needs to come up before they can be woken up??
Author:  outbreak198x [ May 8th, 2024, 17:21 ]
Post subject:  Re: Samsung SSD 840 PRO no longer being recognized by bios
fzabkar wrote:
I would replace RT9991. Perhaps V5 and V8 are asleep, and V2 needs to come up before they can be woken up??


Changed RT9991 - and it's online :) - thx
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